Me again...
So, I am struggling a bit with numbers.
Okay so, if your priority is saving money, the best thing you could probably do is just keep your current car. Say instead of buying a Toyota or anything else, you put the money into a high interest savings account (one of the worst returns, but gets you 3%). You would be making $900/year and keeping $30k available for future expenses. 25% of gas savings is only let’s say $1000 per year. You saved $100/year net, but lost $3k in depreciation of the vehicle and are actually out $2900. You will never win. Buying a new car is a luxury and shouldn’t really be seen as an rational investment.
That being said if you want to compare when you would “breakeven” between a Corolla and a Model 3, it would probably take you keeping the vehicle for 20 years to “make back” the 30k difference (assuming fixed electricity and fuel pricing, 35000kms per year, 3% opportunity cost, minimal maintenance). A model 3 vs. BMW/Benz/Audi/etc is a much different story...hence why Tesla is killing the midsize luxury sedan market.